Water that is free of any entrained solids or gaseous contaminants is desirable for many industrial applications. One such application is the ultrasonic inspection of materials in which water is used as the coupling medium between the sensing element and the material being inspected. In some of these applications, one such being shown and described in U.S. patent application Ser. No. 4,526,038, filed Feb. 13, 1984 by W. A. Box and E. R. Rusiecki, the ultrasonic waves generated by a transducer are emitted therefrom and reflected back thereto from the test body through a column of water. The water employed in such apparatus must be sufficiently clean and free of gas to prevent the accumulation of gas bubbles and/or solids on the surface of the piezo-electric crystal of the transducer where the accumulated contaminants would disrupt the emitted electronic signals.
In the past, it has been the practice to remove the aforementioned contaminants from water used as a coupling medium through the use of commercial filters or settling tanks. The use of filters is, however, undesirable because of their need to be frequently cleaned and/or replaced which results not only in high capital and maintenance costs but also in frequent removal of the apparatus from service. The use of settling tanks for contaminant removal purposes is also undesirable, primarily due to the large space requirements and maintenance attendant with their use. Settling tanks are also of questionable effectiveness in delivering water of adequate cleanliness.
For the purpose of solids removal and deaeration of a liquid, the present invention contemplates the use of a small, compact centrifugal separating apparatus having no moving parts. While centrifugal separators are well-known in the art of fluid purification such apparatus is most commonly employed for the separation of particulate solids from gases. Some, moreover, as shown by U.S. Pat. No. 3,771,290 granted Nov. 13, 1973 to Stethem and U.S. Pat. No. 4,290,791 granted Sept. 22, 1981 to Matsui et al have been employed as liquid deaerators. These known separators, however, suffer from many of the aforementioned disadvantages, namely high capital and maintenance costs and of occupying considerable space, associated with the previously mentioned equipment.
It is to the amelioration of the aforementioned problems, therefore, that the present invention is directed.